Removal of acetylene from gases



Patented June 4, 1946 2,401,444 REMOVAL or sermons mom GASES Charles E.Welling, Bartlesvllle, Okla.., asslznor to Phillips Petroleum Company, acorporation oi Delaware No Drawing. Application January 24, 1942,

Serial No. 428,121

5 Claims. i This invention relates to the removal of acetylene fromcases.

When mixtures of hydrocarbons areprocessed by thermal or catalytictreatment to produce more valuable materials or are treated in someother fashion, it often happens that the presence or even minutequantities of acetylene will give rise to objectionable side reactionsor to deposition of carbon. In consequence it is sometimes desirable totreat such mixtures in such a. fashion as to remove the acetylenewithout destroying valuable components of the mixtures.

It is already known that acetylene may be removed from gases containingit by passing the gases over bauxite or over the usual hydrogens= tioncatalysts such as reduced nickel. With gases containing hydrogen andcertain unsaturated hydrocarbons. undesirable reactions may occur overthese ceteysts in addition to the conversion oi acetylene. Furthermore,such catalysts may present special problems in manufacture and hendlingdue to lack of mechanical strength, need for supporting the activecatalytic material on an inert carrier, dimculty in preparing a.catalyst oi uniform composition and activity, and the like.

I have found that by leading hydrocarbon gases containing acetylene endhydro'genet elevcted temperatures in the rungs 250 to 366 C. overestnlysts oi the suture of glasses the ecetylene may ice very greatlyreduced in amount if not com-=- pletely removed, and this may beaccomplished without destroying? materiel quantities or the valuablehydrocarbons present. Sold glosses rosy be of the type known asborn-silicate glosses. Preferred pressures to be utilized in the processwould lie in the range 500 to 1500 llcsper so. in. It is possible to usethe glass catalyst in vurious forms such as glass wool, chips resultingfrom crushing orgrlndinc end sizing of the particles. tubes. pistes, andthe like. I

Suitable temperatures for operating my process are in the range its to450 (2., and the erect temperature to be used in a particular upplice.tionoi mvprocess will be determined by such factors us flow. velocity ofthe gas over the cutelyst and composition of the gas being treated,permissible acetylene content of the treated gee, previous use of thecatalyst and the like.

The cntelysts according to my invention are relatively immune to sulfurpoisoning and in fact in the form of hydrogen sulfide. mercaptans or thelike. The presence of appreciable amounts of sulfur in the gases to betreated may require some increase in the temperature or the catalystwithin the range already specified. After a. period of use the catalystsaccording to my invention may lose activity and can be rescuersted byburning out in an oxygen-bottling yes stream.

The following exemplerepresents e certein specific embodiment ofprocess. Example l, in which no catalyst was used, is cited merely toshow that very little acetylene can be reected without a catalyst undertheconditlons or temperature and pressure that are comprehended in mycatalytic process. The example is not to lie construed as unnecessarilylimiting the scope of my invention.

v Eccentric i A. synthetic gas mixture containing about 2s per centhydrogen, 7d per cent ethylene nlus propylene, 0.8% acetylene and smallamounts of paramns was passed through c. heated quarts tube. At tubetemperatures of 300 to 325? fin at pressure of 735 to 745 lbsper sq. in,and e space velocity of 90 to 260, from tic-to 91 per cent minutequantities of sulfur, of the order oi e few thousandths of one per centin the gases to be treated. may render the catalyst more selective inltsaction upon the acetylene present and of the acetylene survived andwas found in the efiuent gee.

' Eeample 2 A synthetic gas mixture containing about 23.5 per centhydrogen, 7% per cent propylene plus ethylene, 9.8 per cent scetylene,0.006 per cent hydrogen sulfide and small amounts of poremnicconstituents was treated at too to 740 lbs. per sq. in. pressure and ate. catalyst temperature. of sec to 305 C. The catalyst was composed of u"Pin-ex gloss tube oi about ill mm. interior diameter which was looselyfilled with Pyrex glass wool. The cetelyst tube was maintained at thetemperature indicated above over a. length oi 32 to 38 inches. Thesynthetic cos m be treated was passed through the tube at n how rate ofapprenimetely 28 liters gas (at standard conditions) per hour. A sampleor eifiuent cos contained 0.04 to 0.05 per cent acetylene. Concurrentdestruction hence such amounts of sulfur may be desireble cc of 88895 ofSimilar mp it n-but deficient in hydrogen, hydrogen from an outsidesource may, course, be added in such amounts as may be round necessaryfor any particular case. My invention particularly applies toolefin-containing gases where the olefin content exceeds the acetylenecontent, particularly to gases containing or less of acetylenes, andwill find particular use in the treatment. of gases containing no morethan 1% of acetylenes.

I claim: v 1. A process for hydrcgenating acetylene in a v 4 3. Theprocess of claim 1 in which said mixture contains not more than 1% ofacetylene.

4. The process or claim 1 in which said mixture contains a normallygaseous sulfur-containing compound.

5. A process for removing acetylene from a normally gaseous mixturecontaining tree hydrogen, oleflns, and acetylene in an amount less thanthat of said oleflns and not more than 5% of said mixture, whichvcomprises contacting said mixture at a temperature between about andabout 400 C. under a pressure between about 500 and about 1500 poundsper square inch with a boro-silicate glass, in a form having a largesurface area, for a time such that the eiiluents are substantially freefrom acetylene and such that olefins originally present remainsubstantially um'eacted.

CHARLES E. WEILING.

